Tone-arm for talking-machines



H. SEGAL.

TO NE ARM FOR TALKING MACHINES.

APPLICATION FILED OCT. 25,1919.

Patent ed Dec. 21,1920.

VE/V TOR dz 4 UNITED STATESQPATENT OFFICE.

HERMAN SEGAL, 0F YORK, N. Y.

TONE-ARM FOR TALKING-MACHINES.

ratenteanec. 21, 1920.

1,362,741 Specification of Letters Patent.

Application filed October 25, 1919 Serial No. 333,318.

7 "call to 720m it may concern:

Be it known that I, HERMAN SnoAL, a citizen of the United States, and resident of New York city, in the county of New York and State of New York, have invented certain new and useful Improvements in Tone- Arms for Talking-Machines, of which the following is a specification.

This invention relates to improvements in tone arms for talking machines with special reference to the mounting or bearing which supports the tone arm on the box or cabinet of the machine.

The object of the invention is to provide an improved ball bearing for the tone arm employing but a few number of balls and possessing certain novel features of construction referred to hereinafter.

Accordingly. my invention is embodied in a tone arm as hereinafter described and as illustrated in the accompanying drawing in which Figure 1 is a side view of the tone arm with certain parts in section.

Fig. 2 is a bottom view of the outer ball bearing member or base.

Fig. 3 is a top view of said base.

Fig. 4 is a side View of the lower part of the tone arm with parts broken away.

Fig. 5 is a bottom view of the part shown in Fig. 4.

Referring to Fig. 1 the numeral 6 denotes a tone arm preferably made of metal and having the horizontal branch 7 to which is pivoted at 8 the neck 9 to which the sound boX, not shown, may be attached.

The tone arm is formed with the downwardly extending tapered base portion 19 which has a reduced neck 10 adapted to fit within the slightly tapered base 11. The tone arm is provided with an undercut annular uninterrupted ball race 12 and the top of the base 11 is provided with an interrupted ball race 13, the interruptions being formed by stops or divisions 14, 14. Balls 15, 15 are laid in the said ball races 12-13, one ball in each sector of the ball race 13 or between each two adjacent stops 14 as shown.

The base 11 is undercut to form the lower interrupted ball race 16 and is further provided with an annular enlargement 17 The neck 10 of the tone arm is provided with the lower uninterrupted ball race 18 and an annular recess 29. Balls 20, 20, shown both in Figs. 2 and 5, are laid in the ball races 16-20, one ball in each sector of the ball race 16 between two adjacent stops or divisions 21 therein. 22 is a circular spring which is snapped into position in the recess 29 aforesaid.

In assembling the tone arm and the base,

20 are dropped into the ball races 1618 through channels 23, 23 whichare cut into said races 16-18, one channel for each secfor of the ball race 16.

Thereafter the spring 23 is placed in position in the recess 29 and prevents the balls 20 from falling out, after which the tone arm and bearing are assembled and ready to be mounted on the talking machine cabinet, not shown. The base 11 has a flange 24 through which screws may be passed to attach it to the cabinet. The enlarged annular space 17 affords sufiicient room for the placing of the balls and the attachment of the spring.

In order to limit the horizontal movement of the tone arm with respect to the base, an additional ball 25, Fig. 2, may be dropped into the race 18 which is provided with a stop 26 Fig. 5. There will then be one ball 15 on the one side of the said stop 26, and the ball 25 on the other side of the stop 26. Consequently when the arm swings, its stop 26 will carrythe said ball 15 to the one side against the stop 14 nearest to it, and the ball 25 will be carried against a stop 14 nearest to it on the other side. Hence the tone arms movement is limited between adjaoent stops 14, the said stop 26 working between two balls 15 and 25 as shown. The tone arm base portion 9 may be cast with the ball races, channels and stops therein so these features do not call for anything extra by way of finishing or machine work. Similarly the base may be cast finished with the ball races and stops therein.

The balls form an expensive part in the manufacture of the tone arm and bearing therefor, but by means of the construction set forth above the number of balls is very materially reduced. In some instances the number of balls are reduced from 48 to 9, thus effecting a material saving. It will be noted that the assembling of the tone arm and base may be done very quickly and that besides acting as bearing members, the balls lock the two main parts together and prevent vertical movement of the tone arm Within the base, thereby affording better operation.

I claim The combination of an outer relatively fixed tubular member and an inner rela-- tively movable tu bularkknemben adapted to fit and rotate within said outer member, which latter is provided with an upwardly facing ball race and a downwardly facing ball race, upper and lower antifriction balls in said ball races, equidistantly spaced fixed projections in said ball races integral therewith for dividing the same into sectors in which the said antifriction balls are adapted to run, an upper and a lower ball race formed in the said inner tubular member vadapted to cooperate with the ball races aforesaid to form an upper and a lower ball bearing between the said two members, an annular groove in said inner tubular member, an annular spring in said groove for retaining the said lower antifrietion balls in position, and channels in said inner tubular member for placing the said lower antifriction balls in position.

Signed at New York, in the county of New York and State of New York, this 21st day of October, A. D. 1919.

HERMAN SEGAL. 

